Electric vehicles are rapidly gaining popularity in today's automotive marketplace. Electric vehicles offer several desirable features, such as eliminating emissions and usage of petroleum-based fuels at the consumer level, and potentially lower operating costs. A key component of electric vehicles is the rechargeable energy storage system (RESS), which is typically a battery pack and can represent a substantial proportion of the vehicle's cost. Battery packs in electric vehicles typically consist of numerous interconnected cells, operating at a relatively high voltage, and delivering power on demand. Maximizing battery pack life is a key consideration in the design and operation of electric vehicles.
In order to maximize battery pack life, the temperature in the battery pack must be controlled so that it does not exceed a certain level. Control systems in existing electric vehicles typically prescribe a maximum allowable temperature in the battery pack, and use an onboard thermal management system to prevent battery pack temperature from rising above the prescribed limit. Additionally, the thermal management system may utilize an intrusive diagnostic operation that consumes a large amount of energy and resources to monitor the performance of the thermal management system.
There is an opportunity to employ a non-intrusive active cooling system diagnostic methodology which provides timely analysis by the intrusive diagnostic operation when necessary, but which reduces the diagnostic energy need during typical operation. Such a method could yield cost savings for electric vehicles through the reduction of energy use by the diagnostic mechanisms, and increase customer satisfaction through improved vehicle driving range.
Accordingly, it is desirable to provide electric vehicles with improved methods and systems for diagnosing RESS active cooling systems. In addition, it is desirable to provide non-intrusive methods and systems for diagnosing RESS active cooling systems which use reduced amounts of energy while providing proper diagnostic oversight. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.